Recent characteristics of surgeries include rapidity and greater sophistication. Therefore, limitations of traditional astriction and sutural hemostasis are worthy of attention. A fibrin adhesive, which is a currently commercially available hemostatic agent and a tissue adhesive, has problems involving a high risk of viral infection and a weak adhesive strength (Non-Patent literature 1).
In addition, a polyamine-aldehyde system, which is clinically used in addition to the fibrin adhesive, and which is obtained by hardening gelatin by means of adding cross-linking agents such as formaldehyde, glutaraldehyde or the like, has been found to carry the risk of causing residual disabilities such as vessel-clogging and significant neurological problems and tissue damage due to the presence of low-molecular-weight aldehyde compounds and, therefore, it is unsuitable for use (Non-Patent literature 2).
In order to overcome these problems, a number of studies have been carried out. For example, an adhesive agent derived from the cross-linked Schiff base formation between dextran which is obtained from food additives and ε-poly-L-lysine (hereinafter, called ε-PLL) has been studied, but its gel strength is lower than that of fibrin adhesive which is a commercially available hemostatic agent and this insufficient strength as a hemostatic agent is a problem. Regarding the cause of this problem, it is thought that the periodate oxidation conducted on polysaccharides in order to make them aldehyde causes the ring-opening of main chain glucose of dextran. In the process of this periodate oxidation, aldehyde groups are introduced into the main chain, but, at the same time, the main chain scission occurs and then the molecular weight of dextran decreases, which may bring about a decrease in the gel strength (Non-Patent literature 3).
As an adhesive agent exhibiting excellent strength, a tissue adhesive which comprises active ester derivatives of citric acid and proteins such as collagen as adhesive components has been studied. However, the active ester compound is chemically unstable and it is impossible to store the compound for a long time in the form of an aqueous solution. Therefore, the active ester compound is required to be dissolved immediately before use in solvent which carries the risk of bringing about adverse effects on living organisms. Further, there might be some problems when a medical doctor uses it in an emergency during surgical procedures (Patent literature 1 and Non-Patent literature 4).    [Patent literature 1] JP-A-2004-261222    [Non-Patent literature 1] Masafumi KAWAMURA, Yoshinari KIMURA, Ikuo KAMIYAMA, Takahiko KOYAMA, Taichiro GOTO, Manabu YAMAMOTO, Yoshimasa INOUE, Takashi OTSUKA, Hayanori HORIGUCHI, Tokuko YAMAUCHI, Makoto FUJISAWA, Masazumi WATANABE, Hirohisa HIRINOUCHI, Koichi KOBAYASHI, Journal of Japan Surgery Society, 103, 261 (2002)    [Non-Patent literature 2] D. Guilmet, J. Bachet, B. Goudot, C. Laurian, F. Gigou, O. Bical, M. Barbagelatta, J. Thorac. Cardiovasc. Surg., 77, 516(1979)    [Non-Patent literature 3] Shokyu GEN, Naoki NAKAJIMA, Hajime SUGAI, Sadami TSUTSUMI, J J Dent Mater 25, 401 (2006)    [Non-Patent literature 4] Tetsushi TAGUCHI, Engineering Materials, 55, 41 (2007)